We propose to explore a systematic, general approach to the synthesis of saccharides and related compounds. The approach, in essence, consists of repetition of Sequence A and/or B both of which involve a linear two-carbone extension. These transformations, R-CHO greater than R-*CHOR'-*CHOR'-CHO Sequence A, RCHO greater than R-*CHOR'-CH2-CHO Sequence B, have become feasible with the two highly enantioselective synthetic methodologies: asymmetric eposidation and the asymmetric aldol reaction. Numerous advantages should accrue from this general approach, and higher saccharides with unusual structures will hopefully become readily available. The project begins with the synthesis of all four D-(or L-) pentoses and all eight hexoses with the purpose of perfecting both sequences A and B. The completion of this initial stage will lead to a course of extension and diversification. Thus, the target molecules selected in a second stage are a) heptoses, heptuloses, octoses, and a nonulose, b) desoxy sugars including the 2-deoxy pentoses and hexoses, and the 6-desoxy-hexoses, and unusual sugars and sugar analogs, such as tunicamine and 2-deoxy-2-fluoro-D-arabinose. In addition, we will launch a project aimed at the synthesis of palytoxin (C129H223N3054), one of the structurally most complicated natural products ever isolated. 2-Deoxy-2-fluoro-D-arabinose is an essential component of a synthetic nucleoside analog being developed as an antiviral drug. Tunicamine is a rare eleven-carbon sugar found in the nucleoside antibiotic tunicamycin, a potent inhibitor of glycosidation. Palytoxin is an extremely potent toxin (LD50 0.15 microgram/kg). The biological action activity). It will be interesting to test the biological activity of the synthetic fragments in order to define the structure/activity relationship of the toxin. This joint project will hopefully grow into an important area of research related to immunochemistry, enzymology, and glycoprotein chemistry.